`][38327]
* [`Ipv6Addr` implements `From<[u16; 8]>`][38131]
* [Ctrl-Z returns from `Stdin.read()` when reading from the console on
Windows][38274]
* [std: Fix partial writes in `LineWriter`][38062]
* [std: Clamp max read/write sizes on Unix][38622]
* [Use more specific panic message for `&str` slicing errors][38066]
* [`TcpListener::set_only_v6` is deprecated][38304]. This
functionality cannot be achieved in std currently.
* [`writeln!`, like `println!`, now accepts a form with no string
or formatting arguments, to just print a newline][38469]
* [Implement `iter::Sum` and `iter::Product` for `Result`][38580]
* [Reduce the size of static data in `std_unicode::tables`][38781]
* [`char::EscapeDebug`, `EscapeDefault`, `EscapeUnicode`,
`CaseMappingIter`, `ToLowercase`, `ToUppercase`, implement
`Display`][38909]
* [`Duration` implements `Sum`][38712]
* [`String` implements `ToSocketAddrs`][39048]
Cargo
-----
* [The `cargo check` command does a type check of a project without
building it][cargo/3296]
* [crates.io will display CI badges from Travis and AppVeyor, if
specified in Cargo.toml][cargo/3546]
* [crates.io will display categories listed in Cargo.toml][cargo/3301]
* [Compilation profiles accept integer values for `debug`, in addition
to `true` and `false`. These are passed to `rustc` as the value to
`-C debuginfo`][cargo/3534]
* [Implement `cargo --version --verbose`][cargo/3604]
* [All builds now output 'dep-info' build dependencies compatible with
make and ninja][cargo/3557]
* [Build all workspace members with `build --all`][cargo/3511]
* [Document all workspace members with `doc --all`][cargo/3515]
* [Path deps outside workspace are not members][cargo/3443]
Misc
----
* [`rustdoc` has a `--sysroot` argument that, like `rustc`, specifies
the path to the Rust implementation][38589]
* [The `armv7-linux-androideabi` target no longer enables NEON
extensions, per Google's ABI guide][38413]
* [The stock standard library can be compiled for Redox OS][38401]
* [Rust has initial SPARC support][38726]. Tier 3. No builds
available.
* [Rust has experimental support for Nvidia PTX][38559]. Tier 3. No
builds available.
* [Fix backtraces on i686-pc-windows-gnu by disabling FPO][39379]
Compatibility Notes
-------------------
* [Uninhabitable enums (those without any variants) no longer permit wildcard
match patterns][38069]
* In this release, references to uninhabited types can not be
pattern-matched. This was accidentally allowed in 1.15.
* [The compiler's `dead_code` lint now accounts for type aliases][38051].
* [Ctrl-Z returns from `Stdin.read()` when reading from the console on
Windows][38274]
* [Clean up semantics of `self` in an import list][38313]
* Reimplemented lifetime elision. This change was almost entirely compatible
with existing code, but it did close a number of small bugs and loopholes,
as well as being more accepting in some other [cases][41105].
[37057]: https://github.com/rust-lang/rust/pull/37057
[37761]: https://github.com/rust-lang/rust/pull/37761
[38006]: https://github.com/rust-lang/rust/pull/38006
[38051]: https://github.com/rust-lang/rust/pull/38051
[38062]: https://github.com/rust-lang/rust/pull/38062
[38622]: https://github.com/rust-lang/rust/pull/38622
[38066]: https://github.com/rust-lang/rust/pull/38066
[38069]: https://github.com/rust-lang/rust/pull/38069
[38131]: https://github.com/rust-lang/rust/pull/38131
[38154]: https://github.com/rust-lang/rust/pull/38154
[38274]: https://github.com/rust-lang/rust/pull/38274
[38304]: https://github.com/rust-lang/rust/pull/38304
[38313]: https://github.com/rust-lang/rust/pull/38313
[38327]: https://github.com/rust-lang/rust/pull/38327
[38401]: https://github.com/rust-lang/rust/pull/38401
[38413]: https://github.com/rust-lang/rust/pull/38413
[38469]: https://github.com/rust-lang/rust/pull/38469
[38559]: https://github.com/rust-lang/rust/pull/38559
[38571]: https://github.com/rust-lang/rust/pull/38571
[38580]: https://github.com/rust-lang/rust/pull/38580
[38589]: https://github.com/rust-lang/rust/pull/38589
[38670]: https://github.com/rust-lang/rust/pull/38670
[38712]: https://github.com/rust-lang/rust/pull/38712
[38726]: https://github.com/rust-lang/rust/pull/38726
[38781]: https://github.com/rust-lang/rust/pull/38781
[38798]: https://github.com/rust-lang/rust/pull/38798
[38909]: https://github.com/rust-lang/rust/pull/38909
[38920]: https://github.com/rust-lang/rust/pull/38920
[38927]: https://github.com/rust-lang/rust/pull/38927
[39048]: https://github.com/rust-lang/rust/pull/39048
[39282]: https://github.com/rust-lang/rust/pull/39282
[39379]: https://github.com/rust-lang/rust/pull/39379
[41105]: https://github.com/rust-lang/rust/issues/41105
[`<*const T>::wrapping_offset`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.wrapping_offset
[`<*mut T>::wrapping_offset`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.wrapping_offset-1
[`Duration::checked_add`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.checked_add
[`Duration::checked_div`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.checked_div
[`Duration::checked_mul`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.checked_mul
[`Duration::checked_sub`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.checked_sub
[`File::set_permissions`]: https://doc.rust-lang.org/std/fs/struct.File.html#method.set_permissions
[`IpAddr::is_ipv4`]: https://doc.rust-lang.org/std/net/enum.IpAddr.html#method.is_ipv4
[`IpAddr::is_ipv6`]: https://doc.rust-lang.org/std/net/enum.IpAddr.html#method.is_ipv6
[`Result::unwrap_or_default`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_or_default
[`SocketAddr::is_ipv4`]: https://doc.rust-lang.org/std/net/enum.SocketAddr.html#method.is_ipv4
[`SocketAddr::is_ipv6`]: https://doc.rust-lang.org/std/net/enum.SocketAddr.html#method.is_ipv6
[`String::insert_str`]: https://doc.rust-lang.org/std/string/struct.String.html#method.insert_str
[`String::split_off`]: https://doc.rust-lang.org/std/string/struct.String.html#method.split_off
[`Vec::dedup_by_key`]: https://doc.rust-lang.org/std/vec/struct.Vec.html#method.dedup_by_key
[`Vec::dedup_by`]: https://doc.rust-lang.org/std/vec/struct.Vec.html#method.dedup_by
[`VecDeque::resize`]: https://doc.rust-lang.org/std/collections/vec_deque/struct.VecDeque.html#method.resize
[`VecDeque::truncate`]: https://doc.rust-lang.org/std/collections/vec_deque/struct.VecDeque.html#method.truncate
[`str::repeat`]: https://doc.rust-lang.org/std/primitive.str.html#method.repeat
[`str::replacen`]: https://doc.rust-lang.org/std/primitive.str.html#method.replacen
[cargo/3296]: https://github.com/rust-lang/cargo/pull/3296
[cargo/3301]: https://github.com/rust-lang/cargo/pull/3301
[cargo/3443]: https://github.com/rust-lang/cargo/pull/3443
[cargo/3511]: https://github.com/rust-lang/cargo/pull/3511
[cargo/3515]: https://github.com/rust-lang/cargo/pull/3515
[cargo/3534]: https://github.com/rust-lang/cargo/pull/3534
[cargo/3546]: https://github.com/rust-lang/cargo/pull/3546
[cargo/3557]: https://github.com/rust-lang/cargo/pull/3557
[cargo/3604]: https://github.com/rust-lang/cargo/pull/3604
Version 1.15.1 (2017-02-09)
===========================
* [Fix IntoIter::as_mut_slice's signature][39466]
* [Compile compiler builtins with `-fPIC` on 32-bit platforms][39523]
[39466]: https://github.com/rust-lang/rust/pull/39466
[39523]: https://github.com/rust-lang/rust/pull/39523
Version 1.15.0 (2017-02-02)
===========================
Language
--------
* Basic procedural macros allowing custom `#[derive]`, aka "macros 1.1", are
stable. This allows popular code-generating crates like Serde and Diesel to
work ergonomically. [RFC 1681].
* [Tuple structs may be empty. Unary and empty tuple structs may be instantiated
with curly braces][36868]. Part of [RFC 1506].
* [A number of minor changes to name resolution have been activated][37127].
They add up to more consistent semantics, allowing for future evolution of
Rust macros. Specified in [RFC 1560], see its section on ["changes"] for
details of what is different. The breaking changes here have been transitioned
through the [`legacy_imports`] lint since 1.14, with no known regressions.
* [In `macro_rules`, `path` fragments can now be parsed as type parameter
bounds][38279]
* [`?Sized` can be used in `where` clauses][37791]
* [There is now a limit on the size of monomorphized types and it can be
modified with the `#![type_size_limit]` crate attribute, similarly to
the `#![recursion_limit]` attribute][37789]
Compiler
--------
* [On Windows, the compiler will apply dllimport attributes when linking to
extern functions][37973]. Additional attributes and flags can control which
library kind is linked and its name. [RFC 1717].
* [Rust-ABI symbols are no longer exported from cdylibs][38117]
* [The `--test` flag works with procedural macro crates][38107]
* [Fix `extern "aapcs" fn` ABI][37814]
* [The `-C no-stack-check` flag is deprecated][37636]. It does nothing.
* [The `format!` expander recognizes incorrect `printf` and shell-style
formatting directives and suggests the correct format][37613].
* [Only report one error for all unused imports in an import list][37456]
Compiler Performance
--------------------
* [Avoid unnecessary `mk_ty` calls in `Ty::super_fold_with`][37705]
* [Avoid more unnecessary `mk_ty` calls in `Ty::super_fold_with`][37979]
* [Don't clone in `UnificationTable::probe`][37848]
* [Remove `scope_auxiliary` to cut RSS by 10%][37764]
* [Use small vectors in type walker][37760]
* [Macro expansion performance was improved][37701]
* [Change `HirVec>` to `HirVec` in `hir::Expr`][37642]
* [Replace FNV with a faster hash function][37229]
Stabilized APIs
---------------
* [`std::iter::Iterator::min_by`]
* [`std::iter::Iterator::max_by`]
* [`std::os::*::fs::FileExt`]
* [`std::sync::atomic::Atomic*::get_mut`]
* [`std::sync::atomic::Atomic*::into_inner`]
* [`std::vec::IntoIter::as_slice`]
* [`std::vec::IntoIter::as_mut_slice`]
* [`std::sync::mpsc::Receiver::try_iter`]
* [`std::os::unix::process::CommandExt::before_exec`]
* [`std::rc::Rc::strong_count`]
* [`std::rc::Rc::weak_count`]
* [`std::sync::Arc::strong_count`]
* [`std::sync::Arc::weak_count`]
* [`std::char::encode_utf8`]
* [`std::char::encode_utf16`]
* [`std::cell::Ref::clone`]
* [`std::io::Take::into_inner`]
Libraries
---------
* [The standard sorting algorithm has been rewritten for dramatic performance
improvements][38192]. It is a hybrid merge sort, drawing influences from
Timsort. Previously it was a naive merge sort.
* [`Iterator::nth` no longer has a `Sized` bound][38134]
* [`Extend<&T>` is specialized for `Vec` where `T: Copy`][38182] to improve
performance.
* [`chars().count()` is much faster][37888] and so are [`chars().last()`
and `char_indices().last()`][37882]
* [Fix ARM Objective-C ABI in `std::env::args`][38146]
* [Chinese characters display correctly in `fmt::Debug`][37855]
* [Derive `Default` for `Duration`][37699]
* [Support creation of anonymous pipes on WinXP/2k][37677]
* [`mpsc::RecvTimeoutError` implements `Error`][37527]
* [Don't pass overlapped handles to processes][38835]
Cargo
-----
* [In this release, Cargo build scripts no longer have access to the `OUT_DIR`
environment variable at build time via `env!("OUT_DIR")`][cargo/3368]. They
should instead check the variable at runtime with `std::env`. That the value
was set at build time was a bug, and incorrect when cross-compiling. This
change is known to cause breakage.
* [Add `--all` flag to `cargo test`][cargo/3221]
* [Compile statically against the MSVC CRT][cargo/3363]
* [Mix feature flags into fingerprint/metadata shorthash][cargo/3102]
* [Link OpenSSL statically on OSX][cargo/3311]
* [Apply new fingerprinting to build dir outputs][cargo/3310]
* [Test for bad path overrides with summaries][cargo/3336]
* [Require `cargo install --vers` to take a semver version][cargo/3338]
* [Fix retrying crate downloads for network errors][cargo/3348]
* [Implement string lookup for `build.rustflags` config key][cargo/3356]
* [Emit more info on --message-format=json][cargo/3319]
* [Assume `build.rs` in the same directory as `Cargo.toml` is a build script][cargo/3361]
* [Don't ignore errors in workspace manifest][cargo/3409]
* [Fix `--message-format JSON` when rustc emits non-JSON warnings][cargo/3410]
Tooling
-------
* [Test runners (binaries built with `--test`) now support a `--list` argument
that lists the tests it contains][38185]
* [Test runners now support a `--exact` argument that makes the test filter
match exactly, instead of matching only a substring of the test name][38181]
* [rustdoc supports a `--playground-url` flag][37763]
* [rustdoc provides more details about `#[should_panic]` errors][37749]
Misc
----
* [The Rust build system is now written in Rust][37817]. The Makefiles may
continue to be used in this release by passing `--disable-rustbuild` to the
configure script, but they will be deleted soon. Note that the new build
system uses a different on-disk layout that will likely affect any scripts
building Rust.
* [Rust supports i686-unknown-openbsd][38086]. Tier 3 support. No testing or
releases.
* [Rust supports the MSP430][37627]. Tier 3 support. No testing or releases.
* [Rust supports the ARMv5TE architecture][37615]. Tier 3 support. No testing or
releases.
Compatibility Notes
-------------------
* [A number of minor changes to name resolution have been activated][37127].
They add up to more consistent semantics, allowing for future evolution of
Rust macros. Specified in [RFC 1560], see its section on ["changes"] for
details of what is different. The breaking changes here have been transitioned
through the [`legacy_imports`] lint since 1.14, with no known regressions.
* [In this release, Cargo build scripts no longer have access to the `OUT_DIR`
environment variable at build time via `env!("OUT_DIR")`][cargo/3368]. They
should instead check the variable at runtime with `std::env`. That the value
was set at build time was a bug, and incorrect when cross-compiling. This
change is known to cause breakage.
* [Higher-ranked lifetimes are no longer allowed to appear _only_ in associated
types][33685]. The [`hr_lifetime_in_assoc_type` lint] has been a warning since
1.10 and is now an error by default. It will become a hard error in the near
future.
* [The semantics relating modules to file system directories are changing in
minor ways][37602]. This is captured in the new `legacy_directory_ownership`
lint, which is a warning in this release, and will become a hard error in the
future.
* [Rust-ABI symbols are no longer exported from cdylibs][38117]
* [Once `Peekable` peeks a `None` it will return that `None` without re-querying
the underlying iterator][37834]
["changes"]: https://github.com/rust-lang/rfcs/blob/master/text/1560-name-resolution.md#changes-to-name-resolution-rules
[33685]: https://github.com/rust-lang/rust/issues/33685
[36868]: https://github.com/rust-lang/rust/pull/36868
[37127]: https://github.com/rust-lang/rust/pull/37127
[37229]: https://github.com/rust-lang/rust/pull/37229
[37456]: https://github.com/rust-lang/rust/pull/37456
[37527]: https://github.com/rust-lang/rust/pull/37527
[37602]: https://github.com/rust-lang/rust/pull/37602
[37613]: https://github.com/rust-lang/rust/pull/37613
[37615]: https://github.com/rust-lang/rust/pull/37615
[37636]: https://github.com/rust-lang/rust/pull/37636
[37627]: https://github.com/rust-lang/rust/pull/37627
[37642]: https://github.com/rust-lang/rust/pull/37642
[37677]: https://github.com/rust-lang/rust/pull/37677
[37699]: https://github.com/rust-lang/rust/pull/37699
[37701]: https://github.com/rust-lang/rust/pull/37701
[37705]: https://github.com/rust-lang/rust/pull/37705
[37749]: https://github.com/rust-lang/rust/pull/37749
[37760]: https://github.com/rust-lang/rust/pull/37760
[37763]: https://github.com/rust-lang/rust/pull/37763
[37764]: https://github.com/rust-lang/rust/pull/37764
[37789]: https://github.com/rust-lang/rust/pull/37789
[37791]: https://github.com/rust-lang/rust/pull/37791
[37814]: https://github.com/rust-lang/rust/pull/37814
[37817]: https://github.com/rust-lang/rust/pull/37817
[37834]: https://github.com/rust-lang/rust/pull/37834
[37848]: https://github.com/rust-lang/rust/pull/37848
[37855]: https://github.com/rust-lang/rust/pull/37855
[37882]: https://github.com/rust-lang/rust/pull/37882
[37888]: https://github.com/rust-lang/rust/pull/37888
[37973]: https://github.com/rust-lang/rust/pull/37973
[37979]: https://github.com/rust-lang/rust/pull/37979
[38086]: https://github.com/rust-lang/rust/pull/38086
[38107]: https://github.com/rust-lang/rust/pull/38107
[38117]: https://github.com/rust-lang/rust/pull/38117
[38134]: https://github.com/rust-lang/rust/pull/38134
[38146]: https://github.com/rust-lang/rust/pull/38146
[38181]: https://github.com/rust-lang/rust/pull/38181
[38182]: https://github.com/rust-lang/rust/pull/38182
[38185]: https://github.com/rust-lang/rust/pull/38185
[38192]: https://github.com/rust-lang/rust/pull/38192
[38279]: https://github.com/rust-lang/rust/pull/38279
[38835]: https://github.com/rust-lang/rust/pull/38835
[RFC 1506]: https://github.com/rust-lang/rfcs/blob/master/text/1506-adt-kinds.md
[RFC 1560]: https://github.com/rust-lang/rfcs/blob/master/text/1560-name-resolution.md
[RFC 1681]: https://github.com/rust-lang/rfcs/blob/master/text/1681-macros-1.1.md
[RFC 1717]: https://github.com/rust-lang/rfcs/blob/master/text/1717-dllimport.md
[`hr_lifetime_in_assoc_type` lint]: https://github.com/rust-lang/rust/issues/33685
[`legacy_imports`]: https://github.com/rust-lang/rust/pull/38271
[cargo/3102]: https://github.com/rust-lang/cargo/pull/3102
[cargo/3221]: https://github.com/rust-lang/cargo/pull/3221
[cargo/3310]: https://github.com/rust-lang/cargo/pull/3310
[cargo/3311]: https://github.com/rust-lang/cargo/pull/3311
[cargo/3319]: https://github.com/rust-lang/cargo/pull/3319
[cargo/3336]: https://github.com/rust-lang/cargo/pull/3336
[cargo/3338]: https://github.com/rust-lang/cargo/pull/3338
[cargo/3348]: https://github.com/rust-lang/cargo/pull/3348
[cargo/3356]: https://github.com/rust-lang/cargo/pull/3356
[cargo/3361]: https://github.com/rust-lang/cargo/pull/3361
[cargo/3363]: https://github.com/rust-lang/cargo/pull/3363
[cargo/3368]: https://github.com/rust-lang/cargo/issues/3368
[cargo/3409]: https://github.com/rust-lang/cargo/pull/3409
[cargo/3410]: https://github.com/rust-lang/cargo/pull/3410
[`std::iter::Iterator::min_by`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.min_by
[`std::iter::Iterator::max_by`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.max_by
[`std::os::*::fs::FileExt`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html
[`std::sync::atomic::Atomic*::get_mut`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU8.html#method.get_mut
[`std::sync::atomic::Atomic*::into_inner`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU8.html#method.into_inner
[`std::vec::IntoIter::as_slice`]: https://doc.rust-lang.org/std/vec/struct.IntoIter.html#method.as_slice
[`std::vec::IntoIter::as_mut_slice`]: https://doc.rust-lang.org/std/vec/struct.IntoIter.html#method.as_mut_slice
[`std::sync::mpsc::Receiver::try_iter`]: https://doc.rust-lang.org/std/sync/mpsc/struct.Receiver.html#method.try_iter
[`std::os::unix::process::CommandExt::before_exec`]: https://doc.rust-lang.org/std/os/unix/process/trait.CommandExt.html#tymethod.before_exec
[`std::rc::Rc::strong_count`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.strong_count
[`std::rc::Rc::weak_count`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.weak_count
[`std::sync::Arc::strong_count`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.strong_count
[`std::sync::Arc::weak_count`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.weak_count
[`std::char::encode_utf8`]: https://doc.rust-lang.org/std/primitive.char.html#method.encode_utf8
[`std::char::encode_utf16`]: https://doc.rust-lang.org/std/primitive.char.html#method.encode_utf16
[`std::cell::Ref::clone`]: https://doc.rust-lang.org/std/cell/struct.Ref.html#method.clone
[`std::io::Take::into_inner`]: https://doc.rust-lang.org/std/io/struct.Take.html#method.into_inner
Version 1.14.0 (2016-12-22)
===========================
Language
--------
* [`..` matches multiple tuple fields in enum variants, structs
and tuples][36843]. [RFC 1492].
* [Safe `fn` items can be coerced to `unsafe fn` pointers][37389]
* [`use *` and `use ::*` both glob-import from the crate root][37367]
* [It's now possible to call a `Vec>` without explicit
dereferencing][36822]
Compiler
--------
* [Mark enums with non-zero discriminant as non-zero][37224]
* [Lower-case `static mut` names are linted like other
statics and consts][37162]
* [Fix ICE on some macros in const integer positions
(e.g. `[u8; m!()]`)][36819]
* [Improve error message and snippet for "did you mean `x`"][36798]
* [Add a panic-strategy field to the target specification][36794]
* [Include LLVM version in `--version --verbose`][37200]
Compile-time Optimizations
--------------------------
* [Improve macro expansion performance][37569]
* [Shrink `Expr_::ExprInlineAsm`][37445]
* [Replace all uses of SHA-256 with BLAKE2b][37439]
* [Reduce the number of bytes hashed by `IchHasher`][37427]
* [Avoid more allocations when compiling html5ever][37373]
* [Use `SmallVector` in `CombineFields::instantiate`][37322]
* [Avoid some allocations in the macro parser][37318]
* [Use a faster deflate setting][37298]
* [Add `ArrayVec` and `AccumulateVec` to reduce heap allocations
during interning of slices][37270]
* [Optimize `write_metadata`][37267]
* [Don't process obligation forest cycles when stalled][37231]
* [Avoid many `CrateConfig` clones][37161]
* [Optimize `Substs::super_fold_with`][37108]
* [Optimize `ObligationForest`'s `NodeState` handling][36993]
* [Speed up `plug_leaks`][36917]
Libraries
---------
* [`println!()`, with no arguments, prints newline][36825].
Previously, an empty string was required to achieve the same.
* [`Wrapping` impls standard binary and unary operators, as well as
the `Sum` and `Product` iterators][37356]
* [Implement `From> for String` and `From> for
Vec`][37326]
* [Improve `fold` performance for `chain`, `cloned`, `map`, and
`VecDeque` iterators][37315]
* [Improve `SipHasher` performance on small values][37312]
* [Add Iterator trait TrustedLen to enable better FromIterator /
Extend][37306]
* [Expand `.zip()` specialization to `.map()` and `.cloned()`][37230]
* [`ReadDir` implements `Debug`][37221]
* [Implement `RefUnwindSafe` for atomic types][37178]
* [Specialize `Vec::extend` to `Vec::extend_from_slice`][37094]
* [Avoid allocations in `Decoder::read_str`][37064]
* [`io::Error` implements `From`][37037]
* [Impl `Debug` for raw pointers to unsized data][36880]
* [Don't reuse `HashMap` random seeds][37470]
* [The internal memory layout of `HashMap` is more cache-friendly, for
significant improvements in some operations][36692]
* [`HashMap` uses less memory on 32-bit architectures][36595]
* [Impl `Add<{str, Cow